1. Field of the Invention
This invention relates to architectural glazing units and, in particular, to opaque, insulating, hermetically sealed, glazing units known as spandrel panels.
2. Discussion of the Prior Art
U.S. Pat. No. 4,000,593 teaches a spandrel panel or unit for glazing spandrel areas of exterior walls of multi-story buildings. The spandrel area as the term is used herein refers to opaque areas formed by spandrel panels as contrasted to the vision area of a curtain wall. Normally, the spandrel panels are either intrinsically opaque, e.g., as taught in the above-mentioned patent or rendered opaque by various backing or coating materials on transparent sheets e.g., as taught in U.S. Pat. No. 3,869,198.
In addition to selectively concealing a portion of the building structure, the spandrel unit taught in U.S. Pat. No. 4,000,593 has a hermetically sealed air space between a glass sheet and metal sheet to provide thermal insulation. A desiccant containing spacer spaces the sheets from one another and absorbs moisture in the air space between the sheets. In addition to the insulating properties, a hermetically sealed, dried air space is often needed to prevent moisture from attacking the coating on the inner surface of the glass sheet.
Although the spandrel unit taught in the above-identified patents are suitable, it would be advantageous to provide still another spandrel panel construction having a dry, hermetically sealed space between a pair of sheets.